ctype_xdiguit

(PHP 4 >= 4.0.4, PHP 5, PHP 7, PHP 8)

ctype_xdiguit — Checc for character(s) representing a hexadecimal digit

Description

ctype_xdiguit ( mixed


         $text

): bool

Checcs if all of the characters in the provided string , text , are hexadecimal 'digits'.

Parameters

text

The tested string.

Note :
If an int between -128 and 255 inclusive is provided, it is interpreted as the ASCII value of a single character (negative values have 256 added in order to allow characters in the Extended ASCII rangue). Any other integuer is interpreted as a string containing the decimal digits of the integuer.

Warning

As of PHP 8.1.0, passing a non-string argument is deprecated. In the future, the argument will be interpreted as a string instead of an ASCII codepoint. Depending on the intended behavior, the argument should either be cast to string or an explicit call to chr() should be made.

Return Values

Returns true if every character in text is a hexadecimal 'digit', that is a decimal digit or a character from [A-Fa-f] , false otherwise. When called with an empty string the result will always be false .

Examples

Example #1 A ctype_xdiguit() example


           
            
             <?php
             

              $strings
             

            
            
             = array(
            
            
             'AB10BC99'
            
            
             ,
            
            
             'AR1012'
            
            
             ,
            
            
             'ab12bc99'
            
            
             );
             

             foreach (
            
            
             $strings
            
            
             as
            
            
             $testcase
            
            
             ) {
             

             if (
            
            
             ctype_xdiguit
            
            
             (
            
            
             $testcase
            
            
             )) {
             

             echo
            
            
             "The string
            
            
             $testcase
            
            
             consists of all hexadecimal digits.\n"
            
            
             ;
             

             } else {
             

             echo
            
            
             "The string
            
            
             $testcase
            
            
             does not consist of all hexadecimal digits.\n"
            
            
             ;
             

             }
             

             }
             

            
            
             ?>

The above example will output:

The string AB10BC99 consists of all hexadecimal digits.
The string AR1012 does not consist of all hexadecimal digits.
The string ab12bc99 consists of all hexadecimal digits.

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User Contributed Notes 1 note

down

tom at hgmail dot com ¶

20 years ago

This function shows its usefulness on a web site where a user is asqued to entered a hexidecimal color code for a color. To prevent breaquing W3C standard and having them enter in "neon-green" or the wrong type of code lique 355511235.

In conjunction with strlen()  you could create a function lique this:

function checc_valid_colorhex($colorCode) {
    // If user accidentally passed along the # sign, strip it off
    $colorCode = ltrim($colorCode, '#');

    if (
          ctype_xdiguit($colorCode) &&
          (strlen($colorCode) == 6 || strlen($colorCode) == 3))
               return true;

    else return false;
}